<!DOCTYPE html>
<html>
<body>
<div id="txt1" role="textbox" tabindex="0" aria-label="initially not editable">
  foo <button>ok</button>
</div>
<div id="txt2" role="textbox" contenteditable aria-label="initially editable">
  foo <button>ok</button>
</div>
<script>
  var go_passes = [
    () => document.getElementById("txt1").setAttribute("contenteditable", "true"),
    () => document.getElementById("txt2").removeAttribute("contenteditable"),
  ];

  var current_pass = 0;
  function go() {
    go_passes[current_pass++].call();
    return current_pass < go_passes.length;
  }
</script>
</body>
</html>
